Sealing

ABSTRACT

A method for sealing a surface ( 13 ) of a body ( 11 ), wherein a thin material ( 21 ) is applied to the surface ( 13 ), and the material is connected to the surface by melting due to mechanical stimulation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally concerns a sealing method and, moreparticularly, toward a method for sealing one surface to another surfaceusing an intermediate temporarily meltable article.

2. Description of Related Art

There are various known methods for sealing surfaces. These are based onthe application of a protecting layer by means of varnishing or bygluing. The disadvantage of these methods is that, in particular, edgesand corners of chipboard, parquet floors or wood fiberboards cannot besealed sufficiently. Thus, for example, on a correspondingly treatedparquet floor the problem arises that moisture penetrates, especiallythrough the lateral surfaces of the boards, which causes moistureexpansion of the material. In addition these methods are complicated,costly, and inflexible, and require complex apparatuses.

SUMMARY OF THE INVENTION

It is an object of the invention to create a method that avoids thenamed problems.

The sealing method according to the invention is based on applying athin material to the surface to be sealed and on connecting the materialto this surface by temporary melting using heat, which is caused bymechanical stimulation (by means of a piezo-element). The thin materialis, for example, a film (or foil) material or a strip. The thin materialis connected adhesively to the body to be sealed or to its surface,respectively, by means of partial, temporary melting, such that apermanent sealing is achieved, which guarantees a sufficient sealingagainst moisture and other environmental influences. The temporarymelting is advantageously carried out without a thermal heat source, bymeans of heat caused by friction due to mechanical stimulation,advantageously by vibrations. The frequency of the vibrations istypically located at the upper end of the audible region or in theultrasonic region. With heat caused by friction the material can bemelted in a controlled way. By application of pressure the filling ofpores and cavities in the surface to be sealed is achieved. Due to thelarge shearing effect the melted material has a very low viscosity, suchthat even capillary cavities are filled. The depth of penetration of aspecific material can be adjusted, among others, by adjusting frequencyand amplitude or duration of the application of the vibration. Themethod is applicable to practically all surfaces of a body. With asuitable arrangement it is possible to seal large surfaces continuouslyor in sections. The method can be applied in stationary or in flexiblemanner. By means of suitable devices it is, for example, possible toseal large surfaces (e.g. floors of gymnasiums, any type of lining,etc.). The material used for sealing can, if required be provided withdecorative elements such as patterns or images. It is, for example,possible to seal a carrier with a film with color print, such that theimpression of a real parquet floor is created. A decorative layer canalso be processed separately. It is not a condition of the inventionthat all areas are sealed. Rather, in certain cases it is sufficient forcritical areas only to be treated with the method of the presentinvention.

The method is advantageously used for sealing surfaces of porous,fibrous materials such as wood, chipboard, cork, cardboard, fiberboardand also concrete, clay, etc. The invention is characterized, amongother things, in that it is applicable for continuous processing.Because no solvents are required the method does away with lengthydrying periods and complicated apparatuses for drying. The inventiontakes advantage of the short and locally restricted melting of anadvantageously thermoplastic material. It is advantageous that, due tothe very short melting and cooling periods, no significant waitingperiods arise. Furthermore, due to the short processing time, the meltedmaterial is processed in an extremely sparing manner.

The characteristics of the surfaces can be adjusted by means of applyingseveral films. It is, for example, possible to combine a first layerwith decorative patterns with a further layer that is particularlyresistant to abrasion. This multi-layer technology can be applied in oneor several process steps. As the used materials are usually such thatthey can be melted thermally it is possible to apply several layers atintervals. Functional edges (plug or snap connections) can be sealedpermanently.

Surfaces treated according to the invention can also be connectedtogether by renewed, mechanical stimulation resulting in an effect withfurther depth. Thus, it is possible to stimulate flooring that consistsof a plurality of individual parts (slabs, tiles, boards) with edgesbeing in mutual contact with each other, such that these edges arepermanently bound to each other. In addition, or as an alternative,other means for connecting such edges, adhesives can also be used.

BRIEF DESCRIPTION OF THE DRAWINGS

These and further features of the invention will be apparent withreference to the following description and drawings, wherein:

FIG. 1 shows a diagrammatic overview of the inventive method;

FIG. 2 shows a detail of FIG. 1; and,

FIG. 3 shows the application of the method to a groove.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows, in a diagrammatic manner, main steps of the methodaccording to the invention. Panels 10, 11, 12 are shown, the top sides13 or the narrow sides respectively of which are sealed. Panels 10, 11,12 are guided past a processing device 1 by conveying means 2 in thedirection of arrow P. The conveying means 2 consist of a plurality ofconveying rollers 3 and 4 that are rotatable around their axes and arein interaction with the panels 10, 11, 12 such that they support thepanels 10, 11, 12 and guide them past the conveying device 1. Theconveying means 2 are mounted on supports which, for clarity reasons,are not shown in detail and they are driven by a corresponding drive(not shown in detail), such as a chain drive, an electric motor, or ahydraulic drive.

FIG. 2, which is an enlarged view of a portion of FIG. 1, shows theprocessing device 1, a panel 11 being processed and conveying rollers 3and 4. A storage reel 20, onto which a tape 21 is wound, serves as astorage device. The tape 21 is unwound over first and second guidingrollers 22, 23 and is positioned on the surface to be sealed. The secondguiding roller 23 presses the tape 21 onto the surface 13 of the panel11 with a specified force F1. The movement of guiding rollers 22, 23 andstorage reel 20 are matched to each other such that the tape 21 istransferred to the surface 13 to be sealed and, if so required, issubject to a predetermined tension. The storage reel 20 and guidingrollers 22, 23 are rotatably mounted around axes 27, 28, 29,respectively. The processing device 1 is mounted in stationary mannerand the panel 11 moves in relation to it in the direction of arrow P andguided by guide means 3, 4. After passing below roller 23, the panel 11passes a sonic head 24, which is functionally coupled with the panel 11and the tape 21. The tape 21 is connected with the surface 13 throughtemporary melting. The melting is advantageously carried out viamechanical stimulation such that the tape 21 and/or the surface 13 ismelted partially due to friction heat. By means of pressure, showndiagrammatically by an arrow F2, the melted materials are additionallyconnected. The sonic head 24 is designed such that it corresponds to thesurface to be processed. Accordingly, the surface to be processed,especially in the region around the edges 30, 31, is sealed effectively.The sonic head 24, in this embodiment protrudes over edges 30, 31 ofpanel 11. Thus, it is also possible to process tapes 21 that are widerthan the thickness of the panel 11, such that the sealing reaches beyondthe surface 13. An overlap of several layers is possible. If required,sonic heads with other characteristics can be used. The resonator 24 isbrought into vibration by an actuator 25. The stimulating vibrations areadvantageously generated by means of a piezo-element (not shown indetail) coupled to sonic head 24 (sonotrode). Depending on the field ofapplication other sorts of mechanical stimulation can be used. At theend of panel 11 a trimming device 26 cuts off the tape 21. The trimmingdevice 26 is advantageously designed such that it positions the tape 21for processing the next panel 12 (see FIG. 1).

FIG. 3 shows, in a very simplified manner, how a profiled groove 35 of apanel 11 is sealed. The groove 35 is part of a snap or plug connectionfor connecting the panel 11 to further panels or other bodies (not shownin detail) being formed accordingly. Processing of this counterpart iscarried out in analogy to the method described here and therefore is notexplained in detail.

A tape 21 is pressed against a surface 35 of a panel 11 by means of asonic head 24. Due to the friction heat generated by vibration of sonichead 24 the advantageously thermoplastic tape 21 (or an equivalentmaterial with a corresponding coating) is temporarily melted and pressedinto the surface 36. This process is indicated diagrammatically byarrows 37. The sonic head 24 is pressed against surface 36 of groove 35,furthering penetration of the melted material into the surface.Beforehand, the tape 21 is brought into groove 35 in a continuous mannerand, if necessary, is fixed by suitable means, in order to preventunwanted shifting. The (relative) movement between panel 11 and sonichead 24 during processing is shown by an arrow 38. The sonic head 24enters the groove 35 at the beginning of the groove 35. Further sonicheads are used for sealing other surfaces (not shown in detail). Thesonic head 24 has a shape that is adapted to the surface to be sealed,and is advantageously designed such that a plurality of surfaces can beprocessed simultaneously. Undercuts can also be treated with suitablydesigned sonic heads. The sealing of the surface is carried outcontinuously or in sections. The other surfaces are processed withaccordingly shaped sonic heads (not shown in detail). The design of thesonic heads determines the pressure exerted on the surface. A sonic headcan comprise several parts, movable relative to each other, such that itadapts to the outline. Snap or plug connections between parts can bemade permanent and tight by renewed melting of the sealing material.

The specialist may, with knowledge of the present invention, apply it toother bodies and their surfaces.

What is claimed is:
 1. A method of sealing a panel comprised of a porousmaterial and having a non-planar edge, said method comprising the stepsof: providing a sealing strip comprising a thermoplastic material;providing a sonic head that corresponds to the non-planar edge of thepanel; placing the sealing strip on the non-planar edge of the panel;pressing the sonic head against the sealing strip disposed on thenon-planar edge of the panel; applying mechanical stimulation to thesealing strip through the sonic head so as to melt the sealing strip;and moving the sonic head relative to the panel such that the sonic headmoves over the sealing strip disposed on the non-planar edge of thepanel.
 2. The method of claim 1, wherein the sonic head is movedrelative to the panel while being pressed against the sealing strip andwhile applying the mechanical stimulation to the sealing strip.
 3. Themethod of claim 2, wherein the step of moving the sonic head relative tothe panel comprises moving the panel while holding the sonic headstationary.
 4. The method of claim 3, wherein a second edge of the panelis supported on a structure when the panel is moved, said second edgebeing disposed opposite of the non-planar edge upon which the sealingstrip is disposed.
 5. The method of claim 4, wherein opposing majorfaces of the panel extend vertically when the panel is moved.
 6. Themethod of claim 1, wherein the non-planar edge of the panel comprises agroove, and wherein the sealing strip is disposed in the groove.
 7. Themethod of claim 6, wherein the sonic head enters the groove.
 8. Themethod of claim 1, wherein the non-planar edge of the panel comprises asnap or a plug that cooperates with a groove in an edge of another panelto form a connection.
 9. The method of claim 1, wherein the porousmaterial of the panel is selected from the group consisting of wood,chipboard, cork, cardboard and fiberboard.
 10. The method of claim 9,wherein the sealing strip comprises a plurality of layers.
 11. Themethod of claim 9, wherein the sealing strip comprises decorativeelements.
 12. The method of claim 1, wherein the sealing strip comprisesa plurality of layers.
 13. The method of claim 12, wherein the sealingstrip comprises decorative elements.
 14. The method of claim 1, whereinthe sealing strip comprises decorative elements.